1. Field of the Invention
The present invention relates to a high-resolution 2D-3D switchable autostereoscopic display apparatus, and more particularly, to a high-resolution 2D-3D switchable autostereoscopic display apparatus in which a degradation of the resolution is counteracted and crosstalk is reduced.
2. Description of the Related Art
A 3D display apparatus produces a left eye image and a right eye image having a binocular parallax and separately directs the left and right eye images to a left eye and a right eye, respectively. The user recognizes the left eye image and the right eye image provided by the 3D display apparatus through the retina of the corresponding eyes and thus can see a stereoscopic 3D image. Generally, 3D display apparatuses can be roughly classified into a parallax barrier type 3D display apparatus and a lenticular type 3D display apparatus.
In the parallax barrier 3D display apparatuses, a left eye image and a right eye image are displayed on alternating vertical columns of pixels and separated through a very thin vertical lattice, that is, a barrier. The left eye image in a vertical column and the right eye image in a vertical column are separated by the barrier, so that the left and right eyes respectively receive images of different view points to thereby see a 3D image. Referring to FIG. 1, a lenticular type 3D display apparatus 10 generally includes an image display panel 11 including left and right pixels L and R that are alternately arranged to display a right eye image and a left eye image, respectively, and a lenticular lens sheet 12 installed in front of the image display panel 11 to separate the viewing zones of the left eye image and the right eye image.
In a conventional 3D image display apparatus as described above, the left eye image and the right eye image are displayed at the same time on a single image display panel, and thus the resolution of the 3D image the user sees is half of the resolution of the image display panel. Moreover, a complicated structure is required to be able to switch between a 2D image mode and a 3D image mode.
Accordingly, a 3D image display apparatus which can provide a 3D image without a reduction in resolution using a fast response liquid crystal display (LCD) having a refresh rate of 120 Hz is being developed.
FIG. 2 is a schematic view of a conventional 2D-3D switchable autostereoscopic display apparatus 20, which is disclosed in U.S. Pat. No. 5,969,850. Referring to FIG. 2, the 3D image display apparatus 20 includes a backlight unit 21, a spatial light modulator 22, a lenticular lens sheet 23, and a fast response LCD panel 26. The spatial light modulator 22 includes a plurality of cells 24 and 25, which are switched between a transparent state and an opaque state according to the ON/OFF state of the power supplied thereto. The LCD panel 26 alternately displays the left eye image and the right eye image on the entire screen at a fast refresh rate. The spatial light modulator 22 is synchronized with the switching time of the left and right eye images of the LCD panel 26 to switch the cells 24 and 25 into the transparent or opaque state. For example, while the LCD panel 26 is displaying a left eye image, the spatial light modulator 22 switches the left eye cell 24 to a transparent state, and thus the light emitted from the backlight unit 21 heads only to the left eye viewing zone 28 of the user. While the LCD panel 26 is displaying a right eye image, the spatial light modulator 22 switches on the right eye cell 25 so that the light emitted from the backlight unit 21 heads only to the right eye viewing zone 27 of the user. In a general 2D mode, all of the cells 24 and 25 of the spatial light modulator 22 are turned on.
However, in U.S. Pat. No. 5,969,850, crosstalk occurs between a left eye image and a right eye image for the following reasons, and thus the user cannot watch an accurate 3D image.
In general, most image display panels scan a frame from top to bottom. Thus, while a previous frame is being displayed at the bottom of the screen, the next frame is displayed at the top of the screen. As illustrated in FIG. 3, when T indicates the time required to completely scan one frame, a right eye image is displayed on the entire screen at time 0, and a left eye image is displayed on the entire screen at time T. However, since the right eye image is continually changing to the left eye image between time 0 and time T, the left eye image is displayed at the top of the screen and at the same time the right eye image is displayed at the bottom of the screen. As a result, there exists a period when the left eye image and the right eye image share the screen. Therefore, as in U.S. Pat. No. 5,969,850, when the left eye cells 24 and the right eye cells 25 of the spatial light modulator 22 are simply alternately turned on and off, the left eye image and the right eye image may not be completely separated and sensed by the left eye and the right eye of the user at the same time, so that serious crosstalk may be generated.